OOS 41
Restoration, Distribution, and Ecology of Tamarix, A Ubiquitous Exotic Species

Thursday, August 14, 2014: 1:30 PM-5:00 PM
203, Sacramento Convention Center
Anna A. Sher, University of Denver
Tom L. Dudley, University of California, Santa Barbara; William S. Longland, USDA, Agricultural Research Service; and Kenneth Lair, DBA Lair Restoration Consulting
Anna A. Sher, University of Denver
Few plant species have been as successful throughout the American West as Tamarix (tamarisk, saltcedar), nor have any had as much combined scientific, public, and political attention. Several species of Tamarix have been brought from Eurasia since the 1800s, and the resultant hybrid swarm has been successful in many environments, from riparian zones to arid terraces to urban areas. The combined effects of climate change and rapid evolution of the species is likely to expand its range further in elevation and latitude. Tamarix grows in many places where native trees cannot, which has important consequences for animals that are able to exploit the new shrub. The successful introduction of Diorhabda spp, a defoliating beetle, may affect the behavior of the Southwestern willow flycatcher, which in some areas has transferred its former preference from native willows to the newly dominant Tamarix. Thus, controversy continues about the value of Tamarix in both ecological and anthropogenic terms, critically influencing both policy and management practices. Speakers will give presentations on range and distribution, urban ecology, interactions with animals including the biological control beetle, and the plant’s response to restoration activities.


1) Understand the role of exotic Tamarix in ecosystems at various trophic levels

2) Explore the current and future range of the species and its ecological consequence

3) Develop a consensus in priorities for both science and management

Importance and interest to ESA membership: This truly cosmopolitan tree provides an excellent focus for considering issues in species conservation, ecosystem management, and how species spread into novel environments. Tamarix is now the most common riparian tree in the west and in many places is a target for both conservation and restoration. Many millions of dollars are being spent on its removal, but often with little understanding about the consequences of these actions. Communication among many scientific disciplines is critical for understanding both the significance of Tamarix as a case study in exotic plant introductions, and how they might be managed in the future. This organized oral session is relevant to the fields of population ecology, invasive species science, ecological forecasting, landscape ecology, plant-animal interactions, conservation biology, urban ecology, and restoration ecology.

1:30 PM
 Current and projected distributions of Tamarix in North America
Catherine Jarnevitch, United States Geological Survey; James J. Graham, Humboldt State University; Paul H. Evangelista, Colorado State University
2:10 PM
 Tamarix invasion and management in the northern U.S
Michelle Ohrtman, South Dakota State University; Sharon A. Clay, South Dakota State University; Alexander Smart, South Dakota State University
2:30 PM
 Tamarix removal in the context of restoration
Cameron H. Douglass, Trinity College; Scott J. Nissen, Colorado State University
2:50 PM
 Tamarisk biocontrol: A case study in rapid evolution and range expansion of an introduced species
Dan Bean, Colorado Department of Agriculture; Tom L. Dudley, University of California, Santa Barbara; Peter Dalin, Swedish University of Agricultural Sciences
3:10 PM
3:40 PM
 Plant community shifts over time in Tamarix removal sites with and without biological control
Anna A. Sher, University of Denver; Hisham El Waer, University of Denver; Eduardo González, University of Denver
4:00 PM
 Tamarix as wildlife habitat
Heather L. Bateman, Arizona State University Polytechnic; William S. Longland, USDA, Agricultural Research Service; Matthew J. Johnson, Northern Arizona University
4:20 PM
 Influences of environmental conditions and genetic status on dieback and mortality of Tamarix in response to biological control
Tom L. Dudley, University of California, Santa Barbara; Kevin R. Hultine, Desert Botanical Garden; Dan Bean, Colorado Department of Agriculture
4:40 PM
 Tamarix invasion and fire in desert riparian ecosystems
Gail M. Drus, Saint Francis University; Tom L. Dudley, University of California, Santa Barbara; Matthew L. Brooks, United States Geological Survey; J.R. Matchett, USGS Western Ecological Research Center; Thomas J. Even, University of California